chapter 4

Question 1

do programmers approach a new project fast and easy?

Answer 1

Don’t believe the wise guys who say they never go through careful step by steps when programming. Even experienced programmers approach a new project slowly and carefully.

Question 2

what kind of program displays in the console view?

Answer 2

When you run a text based program, the input and output appears in Eclipse’s Console view.

Question 3

what is a GUI program?

Answer 3

a GUI (graphical user interface) program displays windows, buttons, text fields, and other widgets to interact with the user.

Question 4

What are the similarities between English and Java and what are the differences and which ones easier to learn?

Answer 4

English expresses ideas to people, and Java expresses ideas to computers. What’s more, both English and Java have things like words, names, and punctuation. In fact, the biggest difference between the two languages is that Java is easier to learn than English. (If English were easy, computers would understand English. Unfortunately,

Question 5

is it important when using capitals or lower case letters in your code? why?

Answer 5

The java proGRAMMing lanGUage is case-sensitive. ThIS MEans that if you change a lowerCASE LETTer in a wORD TO AN UPPercase letter, you chANge the wORD’S MEaning. ChangiNG CASE CAN MakE the enTIRE WORD GO FROM BeiNG MEANINGFul to bEING MEaningless.

Question 6

can you change the meaning of a java keyword?

Answer 6

Java keyword has a specific meaning — a meaning that remains unchanged from one program to another.

Question 7

what 3 words are not java keywords but can be mistaken as keywords?

Answer 7

true, false, and null are not called Java keywords.

Question 8

what do java keywords posess that is predetermined? who created the java keywords?

Answer 8

In Java, each keyword has an official, predetermined meaning. The people at Oracle, who have the final say on what constitutes a Java program, created all of Java’s keywords.

Answer 9

You can’t make up your own meaning for any of the Java keywords. For example, you can’t use the word public in a calculation:

Question 10

can you change the meaning of a java keyword?

Answer 10

You can’t make up your own meaning for any of the Java keywords. For example, you can’t use the word public in a calculation:

Question 11

what is a java identifier?

Answer 11

In computer programming, an identifier is a noun of some kind. An identifier refers to a value, a part of a program, a certain kind of structure, or any number of things.

Question 12

how does an identifier name relate to it’s meaning? where can you find the definition of java identifiers?

Answer 12

Most programming languages have identifiers with agreed-upon meanings. In Java, almost all these identifiers are defined in the Java API.

Question 13

what is a literal in Java?

Answer 13

A literal is a chunk of text that looks like whatever value it represents.

Question 14

what symbol is permissible when writing numbers as literals in a java program?

Answer 14

Starting with Java 7, numbers with underscores are permissible as literals.

Question 15

in java what do curly braces act like?

Answer 15

A pair of curly braces acts like a box.

Question 16

why is it important to indent your code carefully?

Answer 16

I can’t emphasize this point enough: If you don’t indent your code or if you indent but you don’t do it carefully, your code still compiles and runs correctly. But this successful run gives you a false sense of confidence. The minute you try to update some poorly indented code, you become hopelessly confused.

Question 17

how important is indenting your code?

Answer 17

Take my advice: Keep your code carefully indented at every step in the process. Make its indentation precise, whether you’re scratching out a quick test program or writing code for a billionaire customer.

Question 18

how do you indent your code automatically with Eclipse?

Answer 18

Eclipse can indent your code automatically for you. Select the .java file whose code you want to indent. Then, on Eclipse’s main menu, choose Source ⇒   Format. Eclipse rearranges the lines in the editor, indenting things that should be indented and generally making your code look good.

Question 19

what are the 2 purposes for comments in a java program?

Answer 19

Instead, the comment tells other programmers something about your code.

Comments are for your own benefit, too. Imagine that you set aside your code for a while and work on something else. When you return later to work on the code again, the comments help you remember what you were doing.

Question 20

what are the three types of comments in Java?

Answer 20

The Java programming language has three kinds of comments:
Traditional comments
End-of-line comments
Javadoc comments

Question 21

how do your write a traditional comment and how does it work?

Answer 21

traditional comments begin with /* and ends with /. Everything between the opening / and the closing / is for human eyes only. Nothing between / and */ gets translated by the compiler.

extra asterisks. I call them “extra” because these asterisks aren’t required when you create a comment. They just make the comment look pretty.

Question 22

how do you write an end of line comment and what does it do?

Answer 22

An end-of-line comment starts with two slashes and extends to the end of a line of type.

Question 23

why would anyone comment out some code rather than deleting code when testing suspicious code?

Answer 23

You may hear programmers talk about commenting out certain parts of their code. When you’re writing a program and something’s not working correctly, it often helps to try removing some of the code. If nothing else, you find out what happens when that suspicious code is removed. Of course, you may not like what happens when the code is removed, so you don’t want to delete the code completely. Instead, you turn your ordinary Java statements into comments.

Question 24

how do you write a javadoc comment and what can a javadoc create?

Answer 24

A special Javadoc comment is any traditional comment that begins with an extra asterisk:This is a cool Java feature. The Java SE software that you download from Oracle’s website includes a little program called javadoc. The javadoc program looks for these special comments in your code. The program uses these comments to create a brand-new web page — a customized documentation page for your code.

Question 25

what is a method?

Answer 25

a method is a bunch of instructions collected together and given a new name.

Question 26

what is the relationship of a method header and a body similar to?

Answer 26

A method’s header and body are like an entry in a dictionary. An entry doesn’t really use the word that it defines. Instead, an entry tells you what happens if and when you use the word

Question 27

What is a method in Java?

Answer 27

A block of code that performs a specific task and can be called when needed.

Question 28

What is a method call?

Answer 28

The act of invoking a method using its name and passing any required arguments.

Question 29

What is the method body?

Answer 29

The code inside the curly braces {} of a method that contains the logic to execute.

Question 30

What is a method declaration?

Answer 30

The first part of the method definition that specifies its return type, name, and parameters.

Question 31

what is a statement and how many things can it do in a java program?

Answer 31

In Java, a direct instruction that tells the computer to do something is called a statement.The statements in programs may tell the computer to put 7 in a certain memory location or make a window appear on the screen. The statements in computer programs do all kinds of things.

Question 32

what characteristic helps you know what is a statement?

Answer 32

In Java, each statement ends with a semicolon.

Question 33

does a method header tell the computer what to do?

Answer 33

The method header doesn’t directly tell the computer to do anything. Instead, the method header describes some action for future reference. The header announces “Just in case someone ever calls the method, the next few lines of code tell you what to do in response to that call.”

Question 34

what is the difference between a statement, a header or a declaration?

Answer 34

Every complete Java statement ends with a semicolon. A method call is a statement, so it ends with a semicolon, but neither a method header nor a method declaration is a statement.

Question 35

what is the purpose for the method System.out.println?

Answer 35

Whenever you call the System.out.println method, the computer displays text on its screen.

Question 36

why would programmers want to change the acronym OOP to COP?

Answer 36

Some people want to change the acronym object oriented programming (OOP) and call it COP — class-oriented programming. That’s because object-oriented programming begins with something called a class. In Java, everything starts with classes, everything is enclosed in classes, and everything is based on classes. You can’t do anything in Java until you’ve created a class of some kind.

Question 37

what character appears at the end of a class? what is the purpose for this character? and why do you need this character in your code?

Answer 37

after a class comes a curly brace and the braces mark all the stuff inside the class. without braces you’d know where the class begins but you wouldn’t know where the declaration ends.

Question 38

why do you need curly braces in your java code?

Answer 38

You use curly braces. These curly braces tell the compiler where a chunk of code begins and ends.

Question 39

why do you need to indent your code?

Answer 39

You indent code. Indentation tells your human eye (and the eyes of other programmers) where a chunk of code begins and ends.